Hot super-Earths stripped by host stars found

Scientists using data from NASA's Kepler space telescope have discovered a class of extrasolar planets whose atmospheres have been stripped away by their host stars.
According to the study by astrophysicists at the University of Birmingham in the UK, planets with gaseous atmospheres that lie very close to their host stars are bombarded by a torrent of high-energy radiation.
Due to their proximity to the star, the heat that the planets suffer means that their 'envelopes' have been blown away by intense radiation.
This violent 'stripping' occurs in planets that are made up of a rocky core with a gaseous outer layer.

The scientists used asteroseismology to characterise the stars and their planets to levels of accuracy not achieved before for these systems.
Asteroseismology uses the natural resonances of stars to show their properties and inner structures.

The results of the study have important implications for understanding how stellar systems, like our own solar system, and their planets, evolve over time and the crucial role played by the host star.
"For these planets it is like standing next to a hairdryer turned up to its hottest setting," said Dr Guy Davies, from the University of Birmingham's School of Physics and Astronomy.
"There has been much theoretical speculation that such planets might be stripped of their atmospheres. We now have the observational evidence to confirm this, which removes any lingering doubts over the theory," said Davies.

"Our results show that planets of a certain size that lie close to their stars are likely to have been much larger at the beginning of their lives. Those planets will have looked very different," said Davies.
Scientists expect to discover and characterise many more of these "stripped systems" using a new generation of satellites, including the NASA Transiting Exoplanet Survey Satellite (TESS) Mission which will be launched next year.
The research was published in the journal Nature Communications.